Thermal infrared studies of asteroids afford planetary scientists the opportunity to study the physical and mineralogical properties of asteroids: size, albedo, surface roughness and composition. For the purposes of this article, we define the thermal infrared to be the spectral region beyond 5 μm. For asteroids, which are illuminated by the Sun, the spectral region beyond 5 μm is dominated by radiation thermally emitted from the asteroids themselves. Below 2.5 μm, their flux is dominated by reflected solar radiation, and between 2.5 and 5 μm is a transition region (Figure A43). The wavelength where this transition occurs is strongly dependent on the asteroid's albedo, solar distance and thermophysical properties.
A comparison of the reflected and thermal flux from two 100-km radius asteroids. (a) Both asteroids at 1 AU from the Sun, one with a geometric albedo of 0.05 and one with a geometric albedo of 0.20, typical of C- and S-class asteroids respectively. While the...
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Lebofsky, L.A. (1997). Asteroid: Thermal infrared studies . In: Encyclopedia of Planetary Science. Encyclopedia of Earth Science. Springer, Dordrecht. https://doi.org/10.1007/1-4020-4520-4_26
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DOI: https://doi.org/10.1007/1-4020-4520-4_26
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